Digital-to-Analog Converters (DACs) are used for a wide range of applications. For example, DACs may be used in wireless transmitters to convert digital signals generated by the transmitter's baseband to appropriate analog signals for transmission by an antenna. In a typical transmitter, a digital signal is first converted to an analog signal using a DAC, and then the analog signal is passed through filters, mixers, and amplification stages to generate an upconverted RF analog signal ready for power amplification and transmission.
Existing techniques require a large number of functional blocks to process the signals, which requires a large silicon area on the transmitter integrated circuit (TXIC). Further, existing techniques require a large amount of analog signal processing. These problems make it more difficult to implement transmitters using, for example, modern Complimentary Metal Oxide Semiconductor (CMOS) manufacturing techniques.
Power consumption represents another important design parameter. In many wireless transmitter designs, such as those used in mobile telephones, it is often necessary to minimize power consumption, and therefore to use a low voltage power supply. However, the reliance on the performance of many analog components in existing designs results in either increased power consumption requirements, or reduced performance in low power designs.